Reduced pressure, compression systems and apparatuses for use on joints

ABSTRACT

A system for providing reduced-pressure treatment to a moveable tissue site, such as a joint, includes a flexible dressing bolster. The flexible dressing bolster has a first side and a second, inward-facing side, and a plurality of flexion joints formed on the flexible dressing bolster. The system further includes a sealing subsystem for providing a fluid seal over the flexible dressing bolster and the patient&#39;s epidermis and a reduced-pressure subsystem for delivering a reduced pressure to the sealing subsystem. The sealing subsystem and reduced-pressure subsystem are operable to deliver a reduced pressure to the moveable tissue site. The flexible dressing bolster is operable to allow articulation or movement of the moveable tissue site. The sealing subsystem may include a drape with folds. Other systems, apparatuses, and methods are presented.

RELATED APPLICATIONS

The present invention claims the benefit, under 35 USC §119(e), of thefiling of U.S. Provisional Patent Application Ser. No. 61/057,807,entitled “Reduced-pressure Surgical Wound Treatment System,” filed May30, 2008; U.S. Provisional Patent Application Ser. No. 61/057,798,entitled “Dressing Assembly For Subcutaneous Wound treatment UsingReduce Pressure,” filed May 30, 2008; U.S. Provisional PatentApplication Ser. No. 61/057,808, entitled “See-Through, Reduced-PressureDressing,” filed May 30, 2008; U.S. Provisional Patent Application Ser.No. 61/057,802, entitled “Reduced-Pressure Dressing Assembly For Use inApplying a Closing Force,” filed May 30, 2008; U.S. Provisional PatentApplication Ser. No. 61/057,803, entitled “Reduced-Pressure,Linear-Wound Treatment System,” filed May 30, 2008; U.S. ProvisionalPatent Application Ser. No. 61/057,800, entitled “Reduced-Pressure,Compression System and Apparatus for use on a Curved Body Part,” filed,May 30, 2008; U.S. Provisional Patent Application Ser. No. 61/057,797,entitled “Reduced-Pressure, Compression System and Apparatus for use onBreast Tissue,” filed May 30, 2008; U.S. Provisional Patent ApplicationSer. No. 61/057,805, entitled “Super-Absorbent, Reduced-Pressure WoundDressing and System,” filed May 30, 2008; U.S. Provisional PatentApplication Ser. No. 61/057,810, entitled “Reduced-Pressure, CompressionSystem and Apparatus for use on a Joint,” filed May 30, 2008; U.S.Provisional Patent Application Ser. No. 61/121,362, entitled“Reduced-Pressure Wound treatment System Employing an AnisotropicDrape,” filed Dec. 10, 2008; and U.S. Provisional Patent ApplicationSer. No. 61/144,067, entitled “Reduced-Pressure, Compression System andApparatus for use on a Joint,” filed Jan. 12, 2009. All of theseprovisional applications are incorporated herein by reference for allpurposes.

BACKGROUND

The present invention relates generally to medical systems, and moreparticularly, to reduced pressure, compression systems and apparatusesfor use on joints.

Physicians perform millions of surgical procedures each year around theworld. Many of the procedures are performed as open surgery and anincreasing number are performed using minimally invasive surgery, suchas arthroscopic, laparoscopic, and endoscopic procedures. Many of thesurgical procedures involve surgery on a joint, such as arthroscopicknee surgery, arthroplasty, or many others.

Acute wounds are created during surgery, and these wounds require carefor proper healing. In many situations, a sterile, dry gauze is merelyapplied. In some situations, a dressing is applied and a compressiongarment is applied. In the case of surgery on joints, the care of theresultant wounds can be more challenging because a dressing is desiredthat will allow movement of the joint. Consider as one example thecontext of knee surgery. The skin over the knee that is measuredlongitudinally while standing at seven inches stretches to nearly 15inches when the knee is placed in a completely bent position. If thatrange of motion is desired, the dressing would need to be able toaccommodate approximately a 100% stretch.

BRIEF SUMMARY

Shortcomings with devices, systems, and methods for wound care on amoveable tissue site, e.g., a joint, are addressed by the illustrativeembodiments herein. According to an illustrative embodiment, a systemfor providing reduced-pressure treatment to a moveable tissue siteincludes a flexible dressing bolster having a first side and a second,inward-facing side and a plurality of flexion joints formed on thedressing bolster. The system further includes a sealing subsystem forproviding a fluid seal over the flexible dressing bolster and areduced-pressure subsystem for delivering a reduced pressure to thesealing subsystem. The sealing subsystem and reduced-pressure subsystemare operable to deliver a reduced pressure to the moveable tissue site.The flexible dressing bolster is operable to allow movement of themoveable tissue site.

According to one illustrative embodiment, flexible, reduced-pressuredressing assembly for use on a patient's joint includes a flexiblebolster body having a first side and a second side. The bolster body isformed from a bolster material and has a first plurality of bolstermodules formed on a first side of the bolster body, each bolster modulehaving a bolster ridge. The dressing assembly further includes a drapeextending over the bolster ridges of the first side of the bolster body.the drape is formed from an elastomeric material and is operable tostretch longitudinally at least 80 percent of the drape's un-stretchedlength.

According to one illustrative embodiment, flexible closing dressingbolster for use with a system for treating a linear wound on a patient'sjoint includes a bolster body having a first side and a second,inward-facing side, and is formed with a plurality of flexion joints. Afirst closing member is formed on the bolster body on a firstlongitudinal side of a center wound area. A second closing member isformed on the bolster body on a second longitudinal side of the centerwound area. The first closing member and second closing member areoperable to develop an inward closing force when the closing dressingbolster is placed under reduced pressure.

According to one illustrative embodiment, system for providingreduced-pressure wound treatment to a tissue site includes a flexibledressing bolster and a drape that at least partially covers the flexibledressing bolster. The drape includes a plurality of folds to facilitatebending of the tissue site. The system further includes areduced-pressure source operable to deliver reduced pressure to thetissue site via the flexible dressing bolster.

According to one illustrative embodiment, an apparatus for providingreduced-pressure wound treatment to a tissue site includes a flexibledressing bolster having a first surface and a second, inward-facingsurface. The flexible dressing bolster includes a plurality of flexionjoints. The apparatus further includes a drape at least partially coversthe bolster. The drape includes a plurality of drape-extension devicesto facilitate bending of the apparatus.

Other features and advantages of the illustrative embodiments willbecome apparent with reference to the drawings and the detaileddescription that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be obtainedby reference to the following Detailed Description when taken inconjunction with the accompanying Drawings wherein:

FIG. 1 is a schematic, lateral cross-section of one illustrativeembodiment of a system for providing reduced-pressure wound therapy on amoveable tissue site;

FIG. 2 is a schematic, longitudinal cross-section of a portion of thesystem of FIG. 1 on a knee in an extended (straight) position;

FIG. 3 is a schematic, longitudinal cross-section of the system of FIGS.1 and 2 shown with the knee in the bent position;

FIG. 4 is a schematic, cross-section of a portion of an illustrativeembodiment of a flexible dressing assembly showing a recess;

FIG. 5 is a schematic, perspective view of an illustrative embodiment ofa flexible dressing bolster;

FIG. 6 is a schematic, perspective view of an illustrative embodiment ofa flexible dressing bolster;

FIG. 7 is a schematic, perspective view of an illustrative embodiment ofa flexible dressing bolster;

FIG. 8 is a schematic, perspective view of an apparatus for applyingreduced pressure to a moveable tissue site according to an illustrativeembodiment;

FIG. 9 is a schematic, plan view of the apparatus for applying reducedpressure to the tissue site of FIG. 8;

FIG. 10A is a schematic, longitudinal cross-sectional view of theapparatus in FIG. 9 taken along line 10-10 while the tissue site is inan extended (straight) position;

FIG. 10B is a schematic, longitudinal cross-sectional view of theapparatus in FIG. 9 taken along line 10-10 while the tissue site is in abent position;

FIG. 11 is a schematic, plan view of an apparatus for applying reducedpressure to a tissue site according to an illustrative embodiment;

FIG. 12A is a schematic, perspective view of an illustrative embodimentof another flexible dressing bolster in an extended (straight) position;

FIG. 12B is a schematic, perspective view of the flexible dressingbolster of FIG. 12A shown in a bent position;

FIG. 13 is a schematic, perspective view of an illustrative embodimentof a dressing assembly suitable for use on a joint;

FIG. 14 is a cross sectional view of a portion of the dressing assemblyof FIG. 13; and

FIG. 15 is an exploded, schematic, perspective view of an illustrativeembodiment of a dressing assembly.

DETAILED DESCRIPTION

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings that form a part hereof,and in which is shown, by way of illustration, specific embodiments inwhich the invention may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice theinvention, and it is understood that other embodiments may be utilizedand that logical structural, mechanical, electrical, and chemicalchanges may be made without departing from the spirit or scope of theinvention. To avoid detail not necessary to enable those skilled in theart to practice the invention, the description may omit certaininformation known to those skilled in the art. The following detaileddescription is, therefore, not to be taken in a limiting sense, and thescope of the present invention is defined only by the appended claims.

Referring to FIGS. 1-3, a system 10 for applying a reduced pressure to amoveable tissue site, e.g., an incision 12 in a patient's epidermis 14on or over a joint 18, is presented. The system 10 includes a flexibledressing assembly 30 that includes a flexible dressing bolster 32, asealing subsystem 60, which includes a drape 62, and a reduced-pressuresubsystem 80, which includes a reduced-pressure source 82 andreduced-pressure delivery conduit, or tubing 90.

The dressing assembly 30 includes a flexible dressing bolster 32 thathas a first side 34 and a second, inward-facing, side 36. The flexibledressing bolster 32 has a peripheral edge 38. The flexible dressingbolster 32 may be made of a number of different bolster materials. Inone embodiment, the flexible dressing bolster 32 may be made from aporous and permeable foam-like material and more particularly areticulated, open-cell polyurethane or polyether foam that allows goodpermeability of wound fluids while under a reduced pressure. One suchfoam material is the VAC® Granufoam® Dressings available from KCI of SanAntonio, Tex. Any material or combination of materials may be used forthe bolster material provided that the bolster material is operable tomanifold, or distribute, the reduced pressure. The bolster material mayalso be a combination or layering of materials. For example, a firstbolster layer of hydrophilic foam may be disposed adjacent to a secondbolster layer of hydrophobic foam to form the bolster material. The term“manifold” as used herein generally refers to a substance or structurethat is provided to assist in applying reduced pressure to, deliveringfluids to, or removing fluids from a tissue site. A manifold typicallyincludes a plurality of flow channels or pathways that areinterconnected to improve distribution of fluids provided to and removedfrom the area of tissue around the manifold. Examples of manifolds mayinclude, without limitation, devices that have structural elementsarranged to form flow channels, cellular foam such as open-cell foam,porous tissue collections, and liquids, gels and foams that include orcure to include flow channels.

The reticulated pores of the Granufoam® material, that are in the rangeof about 400 to 600 micron, are helpful in carrying out the manifoldfunction, but other materials may be used. A material with a higherdensity (smaller pore size) than Granufoam® material may be preferable.The bolster material may be a reticulated foam that is later felted to athickness of about ⅓ its original thickness. Among the many possiblematerials, the following may be used: Granufoam® material or a Foamextechnical foam (www.foamex.com). In some instances it may be desirableto add ionic silver to the foam in a microbonding process or to addother substances to the bolster material such as antimicrobial agents.The bolster material may be isotropic or anisotropic depending on theexact orientation of the directed force, e.g., the compressive force,that is desired during reduced pressure. The bolster material could be abio-absorbent material.

Formed on a first side 34 of flexible dressing bolster 32 is a pluralityof flexion joints 40, or flexion areas. The flexion joints 40 areoperable to allow the flexible dressing bolster 32 to flex as theunderlying joint is rotated through its range of motion. The flexionjoints 40 include a resting, or extended, angle of alpha (α) and whenplaced in motion has a bent angle beta (β) (FIG. 3). The flexion joints40 may be formed in a number of different ways. One way to form theflexion joints 40 is to form a plurality of spaced bolster modules 42that define a first plurality 44 of recesses, or notches, betweenbolster modules 42, and that have bolster ridges at an outer mostportion, i.e., the top (for the orientation shown) of each bolstermodule 42. Additional recesses may be formed (e.g., see FIG. 5) and theymay take on different shapes (e.g., see FIG. 7).

The sealing subsystem 60 includes a drape 62, or drape or sealingmember. The drape 62 may be an elastomeric material. “Elastomeric” meanshaving the properties of an elastomer. It generally refers to apolymeric material that has rubber-like properties. More specifically,most elastomers have elongation rates greater than 100% and asignificant amount of resilience. The resilience of a material refers tothe material's ability to recover from an elastic deformation. Examplesof elastomers may include, but are not limited to, natural rubbers,polyisoprene, styrene butadiene rubber, chloroprene rubber,polybutadiene, nitrile rubber, butyl rubber, ethylene propylene rubber,ethylene propylene diene monomer, chlorosulfonated polyethylene,polysulfide rubber, polyurethane, EVA film, co-polyester, and silicones.Specific examples of drape materials include a silicone drape, 3MTegaderm® drape, acrylic drape such as one available from Avery, or anincise drape.

The drape 62 may be disposed adjacent to or coupled to the flexibledressing bolster 32. As used herein, the term “coupled” includescoupling via a separate object, and also includes direct coupling. Inthe case of direct coupling, the two coupled objects touch each other insome way. The term “coupled” also encompasses two or more componentsthat are continuous with one another by virtue of each of the componentsbeing formed from the same piece of material. Also, the term “coupled”includes chemical coupling, such as via a chemical bond. The term“coupled” may also include mechanical, thermal, or electrical coupling.“Coupled” may also mean fixedly coupled or removably coupled.

The coupling between the drape 62 and the flexible dressing bolster 32may occur in many ways. For example, the drape 62 and the flexibledressing bolster 32 may be coupled using adhesives, such as by acrylicadhesive, silicone adhesive, hydrogel, hydrocolloid, etc. The drape 62and the flexible dressing bolster 32 may be bonded by heat bonding,ultrasonic bonding, and radio frequency bonding, etc. The coupling mayoccur in patterns or completely. Structure may be added to the bond tomake the drape 962 behave anisotropically in a desired direction, i.e.,to make an isotropic drape material. An isotropic drape material helpsthe dressing assembly 30 to primarily move in a given direction, i.e.,only about a certain axis or axes.

The drape 62 is sized to extend beyond a peripheral edge 38 of theflexible dressing bolster 32 and to thereby form a drape extension 64.The drape extension 64 has a first side 66 and a second, inward-facingside 68. The drape 62 may be sealed against the epidermis 14 of thepatient using a sealing apparatus 69 for providing a fluid seal, whichallows a reduced pressure to be maintained by the reduced-pressuresubsystem 80. “Fluid seal,” or “seal,” means a seal adequate to maintainreduced pressure at a desired site given the particular reduced-pressuresubsystem involved. The sealing apparatus 69 may take numerous forms,such as adhesive 70, a sealing tape, or drape tape, double-sided drapetape, paste, hydrocolloid, or other sealing means. If a tape is used,the tape may be formed from the same material as the drape 62 with apre-applied, pressure-sensitive adhesive. The pressure sensitiveadhesive 70 may be applied on the second side 68 of the drape extension64. The pressure-sensitive adhesive 70 provides a substantiallyfluid-tight seal between the drape 62 and the epidermis 14 of thepatient. Before the drape 62 is secured to the patient, the adhesive 70may have removable strips covering the adhesive 70. For illustrationpurposes, FIGS. 1 and 2 are shown using a drape tape 71 and FIG. 3 isshown with an adhesive 70.

The reduced-pressure subsystem 80 includes a reduced-pressure source 82,or therapy unit, which can take many different embodiments that providereduced pressure as a part of system 10. The term “reduced pressure” asused herein generally refers to a pressure less than the ambientpressure at a tissue site that is being subjected to treatment. In mostcases, this reduced pressure will be less than the atmospheric pressureat which the patient is located. Alternatively, the reduced pressure maybe less than a hydrostatic pressure of tissue at the tissue site. Unlessotherwise indicated, values of pressure stated herein are gaugepressures. The reduced pressure delivered may be constant or varied(patterned or random) and may be delivered continuously orintermittently. Although the terms “vacuum” and “negative pressure” maybe used to describe the pressure applied to the tissue site, the actualpressure applied to the tissue site may be more than the pressurenormally associated with a complete vacuum. Consistent with the useherein, an increase in reduced pressure or vacuum pressure typicallyrefers to a relative reduction in absolute pressure.

The reduced-pressure source 82 provides reduced pressure for use withinthe system 10. The reduced-pressure source 82 may be any device forsupplying a reduced pressure, such as a vacuum pump, wall suction, orother source. While the amount and nature of reduced pressure applied toa tissue site will typically vary according to the application, thereduced pressure will typically be between −5 mm Hg and −500 mm Hg andmore typically between −100 mm Hg and −300 mm Hg. In order to maximizepatient mobility and ease, the reduced-pressure source 82 is preferablya battery-powered, single-use reduced-pressure generator. Such areduced-pressure source 82 facilitates application in the operating roomand provides mobility and convenience for the patient during therehabilitation phase. Other sources of reduced pressure may be utilized,such as the V.A.C.® therapy unit, which is available from KCI of SanAntonio, Tex., or a wall suction unit. The reduced-pressure source 82could also be supplied by a manually-operated, portable mechanicalmeans, such as a piston in a tube, depending on how much leakage thereis with the fluid seal.

The reduced-pressure source 82 is shown having a battery compartment 84and a canister region 86 with windows 88 providing a visual indicationof the level of fluid within canister region 86. An interposed membranefilter, such as hydrophobic or oleophobic filter, may be interspersedbetween a reduced-pressure delivery conduit, or tubing, 90 and thereduced-pressure source 82.

The reduced pressure developed by the reduced-pressure source 82 isdelivered through the reduced-pressure delivery conduit 90 to areduced-pressure interface 92, which may be an elbow port 94. In oneembodiment, elbow port 94 is a TRAC® technology port available from KCIof San Antonio, Tex. The reduced-pressure interface 92 allows thereduced pressure to be delivered to the sealing subsystem 60 andrealized within an interior portion of the sealing subsystem 60. In thisparticular embodiment, the elbow port 94 extends through or communicatesthrough the drape 62 and into the flexible dressing bolster 32.

If the drape 62 is not already coupled, the drape 62 is placed over thefirst side 34 of the flexible dressing bolster 32 with an extra portionextending beyond the peripheral edge 38 to form the drape extension 64.The drape extension 64 may then be taped down (see 71 in FIG. 1) or anadhesive 70 (FIG. 3) used to form a fluid seal between the drape 62 andthe patient's epidermis 14. The fluid seal need only be adequate toallow the system 10 to maintain a reduced pressure on the desiredtreatment area for a desired time frame. Indeed, some leakage allows fora low velocity air flow that may help with the healing process. Thereduced-pressure interface 92 is applied if not already installed, andthe reduced-pressure delivery conduit 90 is coupled at one end. Theother end of the reduced-pressure delivery conduit 90 is coupled to thereduced-pressure source 82. The reduced-pressure source 82 may then beactivated and reduced pressure delivered to the flexible dressingbolster 32. The reduced pressure may cause a directed force, which mayinclude a compressive force or a closing force, to be developed on thetissue site, e.g., the wound. The force may be a compressive force or insome instance may be a lifting force as discussed further below. Theembodiment shown presents a compressive force.

It may be desirable to apply the system 10 in the operating room andallow the system 10 to remain on the patient until adequate healing hastaken place. In this regard, it may be desirable to form the drape 62,the flexible dressing bolster 32, and any other layers from transparentor translucent materials to allow the healthcare provider to gain visualcues about the healing of wounds without having to remove the dressingassembly 30.

As previously noted, the flexible dressing bolster 32 is adapted toallow the flexible dressing bolster 32 to flex, or move and stretch,with a moveable tissue site, e.g., one associated with an underlyingjoint 18, while providing reduced pressure to the incision 12. Theresultant compression on the incision 12 and any undermined areas belowthe epidermis 14 as well as the reduced pressure supplied to theincision 12 help to remove any voids or defects and help to approximatethe underlying tissues and the combined effect is to reduce edema andfacilitate healing. A closing force may help strengthen the incision 12.

There are a number of ways to form the flexion joints and to otherwisehelp facilitate the flexing of the flexible dressing bolster 32. Theformation of recesses 44, or notches, with the related bolster modules42 on the first side 34 helps the flexible bolster 32 to bend with thejoint 18. The angle between the bolster modules 42, that is the angle inthe recess 44, is initially alpha (α), and as the flexible bolster 32 isbent, the angle goes to a new angle beta (β) where beta (β) is greaterthan alpha (β>α). In one illustrative embodiment, angle alpha (α) isabout 60 degrees and angle beta (β) is about ninety degrees. In anotherillustrative embodiment, angle alpha (α) is about 30 degrees and anglebeta (β) is about sixty degrees. Any of a wide range of possible anglesare possible for angle alpha (α) and angle beta (β).

The drape 62 may be coupled to the bolster modules 42. When a person'sjoint 18 is in the straight, or extended position, the drape 62 may gostraight from one bolster module 42 to the next as shown in FIG. 2. Inan alternative embodiment, the drape 62 may be coupled down in therecesses 44. In another embodiment, the drape 62 may form bubble ridgesover the recesses 44.

Referring now primarily to FIG. 4, a cross-section of a recess 44 isshown with a first side 50 and a second side 52. The first side 50 isshown having a dimension B and the second side 52 is shown with thedimension C. The third dimension A extends from the first side 50 to thesecond side 52 at the top to complete what is shown in cross-section asa triangle. The third side is covered by the drape 62. It will beappreciated that as the flexible dressing bolster 32 is flexed, sides 50and 52 remain the same dimension substantially B, C, but the thirddimension A grows. Thus, the drape 62 that is initially attached with agiven dimension, must be able to stretch considerably. The drape 62 mayneed to stretch any where between 10% and 110% or more (e.g., 20%, 40%,60%, 80%, 100%, 110% or even mores still) of the free (non-stretched)length of the drape 62. Indeed, dimension A can increase by more thanone hundred percent during movement of some joints, and depending theparticular embodiment, the drape 62 will need to accommodate theadditional length. Alternatively or in addition, additional drape 62material may be provided as described in connection with FIG. 8 below tofacilitate extended dimension A.

Referring now primarily to FIG. 5, another illustrative embodiment of aflexible bolster 132 is presented. The flexible dressing bolster 132 isanalogous in most respects to the flexible dressing bolster 32 of theembodiment of FIGS. 1 through 3, but in addition to having a firstplurality of bolster modules 142 with the related recesses 144 allformed on a first side 134 of the flexible dressing bolster 132, asecond plurality of bolster modules 154 are formed on a second side 136of the flexible dressing bolster 132. The bolster modules 154 have theirconcomitant bolster recesses 156.

Referring primarily to FIG. 6, still another illustrative embodiment ofa flexible bolster 232 is presented. The flexible dressing bolster 232is identical to flexible dressing bolster 132 of FIG. 5 except that afirst side recess 258 is formed on a first lateral side 257. Inaddition, a second side recess 259 is formed on a second lateral side261.

Referring now primarily to FIG. 7, another illustrative embodiment of aflexible dressing bolster 332 is presented. The flexible dressingbolster 332 includes bolster modules 342 and accompanying recesses 344,which in this embodiment are formed as semi-circular recesses. It shouldbe noted that virtually any shape may be used for the recesses.

Referring now primarily to FIGS. 8-10B, an apparatus 410, or portion ofa system, for applying reduced pressure to a moveable tissue site isshown according to an illustrative embodiment. The apparatus 410includes a drape 462 that is disposed adjacent to or coupled to anintermediate drape layer 443 to form a pleated structure of drape 462and to at least partially enclose a flexible dressing bolster 432. Thepleated structure of drape 462 includes folds 493 that facilitatebending of the tissue site. As shown in FIG. 10B, the folds 493 may atleast partially unfold when the tissue site is bent and increasedtension is realized on a portion of the drape 462. The tissue site maybe a joint, in which case the folds 493 readily facilitate articulationof the joint. However, the tissue site may also include any tissuecapable of moving, stretching, or bending. The drape 462 and theflexible dressing bolster 432 are otherwise functionally analogous tothe drapes and the bolsters previously shown in FIGS. 1-7 above.

The drape 462 may at least partially cover the flexible dressing bolster432. The flexible dressing bolster 432 has a first side 495 and asecond, inward-facing side 497. A plurality of flexion joints 498 areformed on the first side 495 of the flexible dressing bolster 432. Theflexion joints 498 may be similar in function and design to the flexionjoints 40 described previously herein.

In one embodiment, the drape 462 may partially or fully cover the firstside 495 of the flexible dressing bolster 432. In addition, the drape462 may have a first side 473 and a second, bolster-facing side 475. Thesecond side 475 of the drape 462 may be in direct or indirect contactwith the flexible dressing bolster 432. Although the drape 462 may havea substantially rectangular shape as shown from the plan view of FIG. 9,the drape 462 may have any shape, such as a square, circular,elliptical, or polygonal shape.

The drape 462 includes lateral folds 493, each of which may extend froma first edge 477 of the drape 462 to a second, opposing edge 479 of thedrape 462. The folds 493 may be formed by looping one or more portions483 of the drape 462. Each of the folds 493 may also form a respectiverecess 481 in the drape 462 when the drape 462 is in the straightposition or bent position.

Although the drape 462 is shown to include three folds 493, the drape462 may include any number of folds. For example, the number of folds493 may be varied to accommodate the range of motion of a tissue site,such as a particular joint.

The folds 493 may have any longitudinal length 485. For example, thelongitudinal length 485 of each of the folds 493 may be substantiallyequal. In another example, each of the folds 493 may have a differentlongitudinal length 485. The longitudinal length 485 may also varyrelative to the distance 487 between the folds 493. In one embodiment,the distance 487 between the folds 493 may be greater than thelongitudinal length 485 of the folds 493. In another embodiment, thedistance 487 between the folds 493 may be substantially equal to thelongitudinal length 485 of the folds 493. In yet another embodiment, thelongitudinal length 485 of the folds 493 may be larger than the distance487 between the folds 493.

In one embodiment, the drape 462 may include bond sites 489 that areproximate the folds 493. The bond sites 489 may be operable to adhereeach end 441 of the folds 493 to the first side 473 of the drape 462.The bond sites 489 may include any material capable of providing a bondbetween each end 441 of the folds 493 and the first side 473. Duringbending of the tissue site, as shown in FIG. 10B, each end 441 of thefolds 493 may detach from the first side 473 of the drape 462.

Instead of being positioned externally on the first side 473 of thedrape 462, the folds 493, in another embodiment, may be positionedwithin the flexion joints 498 of the flexible dressing bolster 432.Alternatively, the drape 462 may be substantially contoured to the firstside 495 of the flexible dressing bolster 432 such that the drape 462extends into the flexion joints 498 and is coupled to the flexibledressing bolster 432 within the flexion joints 498.

The apparatus 410 may also include an intermediate drape layer 443,which may include an aperture 445, or treatment-area aperture. Theaperture 445 may provide fluid communication between the apparatus 410and the tissue site. In one embodiment, the drape 462 may include adrape extension 464 around the perimeter of the drape 462. The drapeextension 464 is similar to the drape extension 64 in FIGS. 2 and 3. Thedrape extension 464 may be coupled to the intermediate drape layer 443such that the flexible dressing bolster 432 is at least partiallyenclosed by the drape 462 and the intermediate drape layer 443. Thedrape extension 464 may be coupled to the intermediate drape layer 443as described in any of the illustrative embodiments, and may be coupledusing RF welding, ultrasonic welding, an adhesive material, or anycoupling mechanism.

The intermediate drape layer 443 includes a first side 447 and a second,inward-facing (tissue-facing) side 449. The second, inward-facing side449 may include an adhesive. The second side, inward-facing 449 mayadhere to the tissue site in a variety of ways, such as through the useof an adhesive material on the second side 449.

In one embodiment, the apparatus 410 may also include a tissue-interfacelayer (not shown) that is disposed between the flexible dressing bolster432 and the tissue site. In one example of this embodiment, thetissue-interface layer may be disposed between the intermediate drapelayer 443 and the tissue site. In another example, the tissue-interfacelayer may be at least partially disposed in the aperture 445.

In operation, the apparatus 410 may be applied to a tissue site that ismoveable or bendable, such as a joint. The folds 493 of the drape 462may unfold to accommodate bending of the tissue site, and thus allow thedrape 462 to longitudinally elongate when the tissue site is bent. Inone non-limiting example, as the tissue site is bent, the intermediatedrape layer 443 may be elongated by an increase in arc length, thuscausing the folds 493 of the drape 462, which is coupled to theintermediate drape layer 443 via the drape extension 464, to unfold. Inthis manner, the drape 462 may help to reduce the loading that isexerted onto the tissue site and surrounding area. Reduced pressure mayalso be applied to the tissue site as described in any illustrativeembodiments disclosed herein.

Referring now primarily to FIG. 11, an apparatus 510, or portion of asystem, for applying reduced pressure to a tissue site is shownaccording to an illustrative embodiment. As with the drape 462 in FIGS.8-10B, a drape 562 includes lateral folds 593 that accommodatelongitudinal bending of a tissue site to which the apparatus 510 isapplied. In contrast to the drape 462 in FIGS. 8-10B, the apparatus 510also includes a longitudinal fold 551 that is able to accommodatelateral bending of the tissue site. Thus, the inclusion of lateral folds593 and longitudinal fold 551 allows for the bending of the tissue sitein multiple directions.

The longitudinal fold 551 may extend from one end 553 of the drape 562to an opposing end 555 of the drape 562. Also, although the drape 562 isshown to include one longitudinal fold 551, the drape 562 may includeany number of longitudinal folds 551.

Referring now primarily to FIGS. 12A and 12B, an illustrative embodimentof a flexible closing dressing bolster 846 for use with a system fortreating a linear wound on a patient's joint is presented. “Linearwound” refers generally to a laceration or incision whether in a line ornot. The flexible closing bolster 846 has a bolster body 850 having afirst side 852 and a second, inward-facing (tissue-facing) side 854. Thebolster body 850 is formed from a closing bolster material, i.e., amaterial from which the bolster body 850 is formed. The closing bolstermaterial may be, for example, a silicone material. The bolster body 850is formed with a plurality of flexion joints 848, which are formed withslots 899 that extend from the first side 852 into the bolster body 850.

The bolster body 850 is also formed with a first closing member 856formed on the bolster body 850 on a first longitudinal side of a centerwound area 864. As used here, the term “longitudinal” meanssubstantially parallel to the center wound area 865 as shown—even ifthat dimension is shorter than the other orthogonal, in-plane dimensionof the bolster body 850. A second closing member 858 is formed on thebolster body 850 on the second longitudinal side of the center woundarea 864. Other closing members, e.g., members 860 and 862 may also beformed on the bolster body 850. The first closing member 856 and secondclosing member 858 are operable to develop an inward closing force whenthe flexible closing dressing bolster 846 is placed under reducedpressure. Apertures 851 may be formed on the first side 852 of thebolster body 850 to receive reduced pressure from a reduced-pressuresource (not shown) and a plurality of apertures (not shown) may beformed on the second side 854 to allow the reduced pressure to fluidlycommunicate with a tissue site, e.g., a wound, in the center wound area864.

As reduced pressure enters apertures 851, a central compartment 869 isevacuated and collapses such that a lower portion 871 of the centraltrough 867 contacts a shelf portion 873. In addition, reduced pressureenters into a treatment trough 875 through apertures in the shelfportion 873. The central compartment 871 has slots 899, but the centralcompartment is sealed by a drape. The treatment trough 875 includesoblique walls 877. The reduced pressure in the treatment trough 875 actson the oblique walls 877 and pulls them towards each other. Theseactions cause the bolster body 850 to bend about the central trough 867and causes the contact members on a first lateral side 881 and a secondlateral side 883 to be urged towards each other. This results in aclosing force.

The bolster body 850 may be made from a polymer and is preferably a softpolymer. The flexible closing dressing bolster 846 and the bolster body850 may be made of a transparent material in order to allow the color ofa linear wound to be viewed from a point external to the system or theflexible closing dressing bolster 846. For example, the bolster body 850may be made of a medical grade silicone or other suitable material. Theflexible closing dressing bolster 846 may be extruded, pour molded,injection molded, blow molded, or formed by other manufacturingtechniques. The bolster material may serve to manifold, or distribute,the reduced pressure to the treatment site (e.g., a linear wound),provide a compressive force, and through the closing members provide aninward force—preferably a force that is substantially within the planeof the epidermis. In addition, the bolster material is preferablytranslucent or transparent, to an extent that light may pass throughallowing one to view a wound through the flexible closing dressingbolster 846.

The central trough area 867 helps the bolster body 850 to flex in thatregion as a bending moment is developed under reduced pressure. Thebending moment helps to press the closing members 856, 858, 860, and 862into the patient's epidermis and may provide a directed force with botha downward force and inward force directed towards a central wound area.

Referring now to FIGS. 13-15, and initially to FIGS. 13-14, a portion ofa system 910 for treating a linear wound, area wound, other wound, orgraft is presented. The portion of the system 910 presented in FIG. 15is in a pre-deployment state.

The system 910 includes a dressing assembly 930, which includes aflexible dressing bolster 932. The flexible dressing bolster, or shapeddressing bolster, 932 has a first side 934 and a second, inward-facingside 936. The flexible dressing bolster 932 may be formed from anybolster material as previously discussed with other embodiments. Acomfort layer 970, which has a first side 972 and a second,inward-facing side 974, may be coupled, e.g., by a heat bond 976 or anyother technique, to the second side 936 of the flexible dressing bolster932.

The comfort layer 970 may be any material that helps prevent skinirritation and discomfort while allowing fluid transmission through thecomfort layer 970. As one non-limiting example, a woven, elasticmaterial may be used or a polyester knit textile substrate. As anothernon-limiting example, an InterDry™ textile material from MillikenChemical of Spartanburg, S.C., may be used. The comfort layer 970 mayinclude anti-microbial substances, such as silver.

The flexible dressing bolster 932 may include a plurality of flexibilitynotches 978, or recesses. The flexibility notches 978 may be lateralcuts in the flexible dressing bolster 932 as shown and may furtherinclude one or more longitudinal cuts or other cuts. The flexibilitynotches 978 enhance flexibility of the flexible dressing bolster 932.The enhanced flexibility may be particularly useful when the dressingassembly 930 is applied over a patient's joint or other area ofmovement.

A sealing subsystem 960 provides a fluid seal over the dressing assembly930 and at least a portion of the patient's epidermis. The sealingsubsystem 960 includes a drape 962, which may be formed with a firstdrape portion 963 and a second drape portion 965. The first drapeportion 963 extends over the first side 934 of the flexible dressingbolster 932 and extends further to form a drape flange, or drapeextension 964, which has a first side 966 and a second, inward-facingside (not explicitly shown). An aperture 981 is formed on a portion ofthe first drape 963. The aperture 981 is for allowing fluidcommunication with a reduced-pressure interface (e.g., reduced-pressureinterface 92 in FIG. 1).

The second, inward-facing side of the drape extension 964 is placed on afirst side 967 of the second drape portion 965 and coupled, such as byan adhesive, bond 969, other coupling technique or device, such as thosepreviously mentioned. The first drape portion 963 may include aplurality of folds 973, or bellows. The folds 973 allow additional drapematerial to become available if needed. For example, if the dressingassembly 930 is used on a joint, when the joint is flexed, additionaldrape material may be necessary and the material will be provided fromthe folds 973. The second, inward-facing side of the second drapeportion 965 may have an adhesive on a portion and may have a treatmentarea aperture (see by analogy treatment-area aperture 445 in FIG. 10A).

One or more release members 982 may be releasably coupled to the firstside 967 of the second drape portion 965. Four release members 982 areshown in the illustrative embodiment of FIG. 13. The release members 982provide stiffness and help during deployment of the dressing assembly930. The release members 982 are typically either casting paper or afilm held on the first side 967 of the second drape portion 965.

Referring now primarily to FIG. 15, an exploded perspective view of aportion of a system 1010 for treating tissue, e.g., subcutaneous tissue,a linear wound, area wound, other wound, or graft is presented. Theportion of the system 1010 presented in FIG. 17 is shown in apre-deployment state and in an exploded view. The system 1010 isanalogous in most respects to the system 910 of FIGS. 13-14, and toindicate corresponding parts, the reference numerals have been indexedby 100 and may not be further mentioned. The system 1010 includes adressing assembly 1030, which includes a flexible dressing bolster 1032.The flexible dressing bolster 1032 is the same as flexible dressingbolster 932, but the flexibility notches 1078 are both lateral andlongitudinal.

The first side 1034 of the flexible dressing bolster 1032 is covered bya drape 1062, which may include a first drape portion 1063 and a seconddrape portion 1065. The first drape portion 1063 may include adrape-extension device 1073, such as folds, and an aperture 1081. Thesecond drape portion 1065 is formed with a treatment area aperture 1071that provides an opening for at least a portion of the flexible dressingbolster 1032 (or a comfort layer) to be directly against a patient'sepidermis or treatment site. The second drape portion 1065 has firstside 1067 and has an adhesive 1083 applied on a portion of the firstside 1067. The adhesive 1083 is used primarily during manufacture tohold the flexible dressing bolster 1032 against the second drape portion1065 during assembly and also used to help hold the flexible dressingbolster 1032 during use. Before applying the flexible dressing bolster1032 against the adhesive 1083, the adhesive 1083 is covered by a centerreleaseable member 1084. Outboard of the adhesive 1083 on the first side1067 are releaseable members 1082 that provides stiffness to the drape1062 during deployment. In another embodiment, the drape-extensiondevice 1073 may be a ridge of additional material that provides theability to stretch over longer distances or more readily.

The second, inward-facing side (not explicitly shown but opposite sideof the first side 1067) of the second drape portion 1065 may be coveredwith an adhesive. In the pre-deployment state, this adhesive is coveredby a bottom release member 1086 and side release members 1087.

Once assembled, the portion of the system 1010 resembles the portion ofthe system 910 of FIG. 13. The use and design may vary, but in oneillustrative embodiment, the portion of the system 1010 may be deployedas will be described. The bottom release liner 1086 is removed and theexposed adhesive on the second, inward-facing side of the second drapeportion 1065 is placed against a portion of the patient's epidermisbeginning at one end and may be placed over a linear wound. Aftersmoothly applying the second drape portion 1065, the side releasemembers 1087 are removed. The release members 1082 on the first side1067 of the drape 1062 are removed. A reduced-pressure interface iscoupled to the aperture 1082 in the first drape portion 1063. The centerrelease member 1084 was already removed during manufacture.

In some situations, it may be desirable to have the flexible dressingbolster deliver the force as a lifting force. The density and thicknessof the shaped dressing bolster 1032, which in this embodiment is foam,are variables for controlling lifting. As a substantially thick portionof a flexible dressing bolster 1032 experiences reduced pressure, theflexible dressing bolster 1032 contracts toward a central portion fromall directions. The portion of the flexible dressing bolster 1032 nearthe patient's epidermis pulls away from the patient's epidermis sincethe central portion is above. This creates a radial, lifting force atleast in a center area of the flexible dressing bolster 1032. In may bedesirable to have a flexible dressing bolster 1032 formed from foam thathas a density lighter than the density of the tissue, e.g., epidermis,to which the flexible dressing bolster is applied in order to moreeffectively realize the lifting effect.

According to another illustrative embodiment, a method of manufacturinga flexible, reduced-pressure dressing assembly for use on a moveabletissue site, e.g., a patient's joint, includes the steps of: forming abolster body, which has a first side and a second side, from a bolstermaterial; and forming a first plurality of bolster modules on the firstside of the bolster body. Each bolster module has a bolster ridge. Themethod further includes the step of disposing a drape over the bolsterridges of the first side of the bolster body. The drape is formed froman elastomeric material and is operable to stretch longitudinally atleast 80 percent.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in a connection to any one embodiment mayalso be applicable to any other embodiment.

We claim:
 1. A flexible, reduced-pressure dressing assembly for use on apatient's joint, the dressing assembly comprising: a flexible bolsterbody having a first side and a second side, the bolster body formed froma bolster material; a plurality of flexion joints operable to allow theflexible, reduced-pressure dressing assembly to flex with the patient'sjoint, wherein the plurality of flexion joints comprises a firstplurality of bolster modules formed on a first side of the bolster body,a second plurality of bolster modules formed on the second side of thebolster body, each bolster module having a bolster ridge, and whereineach flexion joint of the plurality of flexion joints has a restingangle alpha greater than or equal to 60 degrees; and a drape extendingover the bolster ridges of the first side of the bolster body, whereinthe drape is formed from an elastomeric material and is operable tostretch longitudinally at least 80 percent of the drape's un-stretchedlength.
 2. The flexible, reduced-pressure dressing assembly for use on apatient's joint of claim 1 wherein the bolster body has a first lateralside and a second lateral side; and further comprising a first siderecess formed on the first lateral side of the bolster body and a secondside recess formed on the second lateral side of the bolster body. 3.The flexible, reduced-pressure dressing assembly for use on a patient'sjoint of claim 1 wherein the drape is coupled to the first plurality ofbolster modules.
 4. An apparatus for providing reduced-pressure woundtreatment to a tissue site, the apparatus comprising: a flexibledressing bolster having a first surface and a second, inward-facingsurface; wherein the flexible dressing bolster includes a plurality offlexion joints formed on said second, inward-facing surface; a drape atleast partially covering the flexible dressing bolster; and wherein thedrape includes a plurality of drape-extension devices to facilitatebending of the apparatus.
 5. The apparatus of claim 4, wherein thedrape-extension devices comprise a plurality of folds.
 6. The apparatusof claim 4, wherein the drape-extension devices comprise comprises,ridges of additional drape material that provides the ability for thedrape to stretch over longer distances.
 7. The apparatus of claim 4,wherein the drape includes a drape extension around a perimeter of thedrape; further comprising an intermediate drape layer having anaperture; and wherein the drape extension of the drape is coupled to theintermediate drape layer to at least partially enclose the flexibledressing bolster.
 8. The apparatus of claim 4, wherein the drapeincludes a drape extension around a perimeter of the drape; furthercomprising an intermediate drape layer having an aperture; wherein thedrape extension of the drape is coupled to the intermediate drape layerto at least partially enclose the flexible dressing bolster; and whereinthe intermediate drape layer has a first side and a second,inward-facing side, and the second side is operable to adhere to thetissue site.
 9. The apparatus of claim 5, wherein the plurality of foldsare operable to unfold when the flexible dressing bolster is bent. 10.The apparatus of claim 5, wherein the plurality of folds includes atleast one lateral fold.
 11. The apparatus of claim 5, wherein the drapehas a first side and a second, inward-facing side; wherein the drapeincludes a plurality of bond sites proximate the plurality of folds; andwherein each of the plurality of bond sites adhere to a portion of thedrape.
 12. The apparatus of claim 5, wherein each of the plurality offolds is formed by looping a portion of the drape.
 13. The apparatus ofclaim 5, wherein the plurality of folds include a first fold and asecond fold, wherein the first fold and the second fold each have alongitudinal length, and wherein a distance between the first and secondfold exceeds the longitudinal length.
 14. The apparatus of claim 5,wherein the plurality of folds include a first fold and a second fold,wherein the first fold and the second fold each have a longitudinallength, and wherein a distance between the first and second fold issubstantially equal to the longitudinal length.
 15. The apparatus ofclaim 4, further comprising: a tissue-interface layer disposed betweenthe flexible dressing bolster and the tissue site.
 16. The apparatus ofclaim 4, further comprising: an intermediate drape layer having anaperture; wherein the drape extension of the drape is coupled to theintermediate drape layer to at least partially enclose the flexibledressing bolster; a tissue-interface layer disposed between the flexibledressing bolster and the tissue site; and wherein the tissue-interfacelayer is at least partially disposed in the aperture of the intermediatedrape layer.